weird white string come out of my Maxima clam's mouth

[colourmop]

just noticed there is this very very very thin string like stuff coming out of my maxima clam's mouth (the tube looking end) is that normal? o.o

 

[nick76]

do u have any tubeworms in the tank?

 

[colourmop]

well, i dont think i have any 'tubeworm' in my tank (new tank, 2 months old) but i do have those tiny worms that burrow in the sand(1 inch long, in the sand bed, transparent)
the thin line thingy from the clam are white/yellowish, and it looks like very thing fish poo but come from inside of the clam, and it is coming out rather than going in, also it is not moving :x
p.s. the clam looks pertty healthy, other than the string. all other clams dont have it.